One of the significant problems inhibiting the further use of synthetic materials is the innate flammability of certain materials, particularly plastics. Recently, certain additives have been added to plastics which provide new compositions that have substantially incresed resistance to flammability. Such a group of additives has been discovered for the polycarbonate materials. Examples of such additives are found in U.S. Pat. No. 3,978,024 which discloses the use of metal salts of phenol ester sulfonic acids in aromatic polycarbonate compositions and U.S. Pat. No. 3,953,399 which discloses the use of the metal salt of sulfonic acids of aromatic carboxylic acids and esters in aromatic polycarbonate compositions. These additives are in general very useful and have successfully extended the uses of aromatic polycarbonates into areas requiring lower levels of inflammability. However, certain properties of the aromatic polycarbonate can be detrimentally affected by the addition of these additives. The presence of the flame retardant additive can bring about a haze in transparent polymeric compositions. Furthermore, destabilization of the composition as shown by increased yellowing index values at high molding temperatures can also occur.
A new group of flame retardant additives has been discovered which maintain or less detrimentally affect the properties of the aromatic carbonate composition than some other flame retardant additives. These new additives are effective at relatively low loading levels.